Metaklett, A Steely Hook And Loop Fastener

From Science Daily:Hook and loop fasteners have become commonplace features of both industry and households. However, they have one snag: they are too weak for many applications. Hook and loop fasteners made of spring steel have now been developed at the Institute of Metal Forming and Casting of the Technische Universitaet Muenchen. These fasteners are resistant to chemicals and can withstand a tensile load of up to 35 tonnes per square meter at temperatures as high as 800°C.

Spring Steel Velco, that’s what we’re talking about here.

Temperatures in excess of 800 °C and aggressive chemical solutions do not pose any problem for Metaklett, which also offers adhesive strength of up to 35 tonnes per square meter when tensile force is applied parallel to the fastener surface. When it is applied perpendicular to the fastener surface, Metaklett can still withstand a force of seven tonnes per square meter. Moreover, like a standard Velcro® fastener on a child’s shoe, it can be opened and closed again without the help of any tools.

You can read the original press release from TUM (Technical University of Munich) in English . A German language version is also available on that page. Use the language buttons in the upper right corner.

Well, the first question is fairly easily answered. Since it is metal, you could drill a hole in it and attach it to something with screws or other fasteners. Or, if you look at this enlargement http://mediatum.ub.tum.de/file/810328/997094.jpgthere are already rectangular cutouts in the band. Perhaps you could attach through them.

The second answer is less clear to me. I wondered about it when I first posted the article. All velcro that I’ve used is unfastened by locally applying enough force to overwhelm a small number of hooks, then moving the load over. This accounts for the ripping sound as they separate. But, as you point out, requires at least one of the surfaces to be flexible.

They do point out in the paper that it has two vastly different strengths, in a 5:1 ratio, depending on load direction. Perhaps they exploit that property somehow. Perhaps a strategic place to insert a crowbar or other lever mechanism.

It’s a steely analogue for regular (plastic) velco. With plastic velcro, a strip of velcro is firmly attached to each item (usually sewn, but you mentioned double sided tape and there are other options too) and then the bond between the two strips of velcro is the one that can be repeatedly opened and closed. Take kids running shoes (I have a grandson with these). The two leather straps have velcro sewn to them, male and female velcro, and then the velcro can be repeatedly opened and closed. There are then a total of 3 interfaces – each piece of velcro to its substrate and then the two types of velcro to each other.

This wouldn’t appear to be substantially different (except for the forces and strengths involved).